Prediction of improvement in ankle blood pressure following arterial bypass

Percutaneous femoral artery pressures and lower extremity segmental Doppler-derived blood pressures in 116 lower extremities were analyzed to determine if postbypass ankle/brachial indices (ABIs) could be predicted based on preoperative pressures. Predicted ABIs were calculated by increasing the prebypass ABI by the same percentage that the extremity/brachial index at the distal end of the bypass would be increased, assuming a postbypass index of 1.0 at the distal graft. The correlation between predicted ABI and actual postbypass ABI was strong for aortofemoral bypass (r = 0.8735) and moderate for infrainguinal bypass (r = 0.5961), with 75% of the postinfrainguinal bypass ABIs being greater than predicted. Minimum postoperative increases in ABI can be predicted based on preoperative hemodynamic measurements, thus providing important information relative to choosing the appropriate level of revascularization in patients with multisegmental disease.